Use of CyberKnife for Lung Cancer Treatment Gets Clinical Data Boost

August 13, 2008 - Following a study published in the July 2008 issue of Clinical Lung Cancer, Accuray Inc. announced today that emerging clinical data continues to support CyberKnife radiosurgery for the treatment of lung cancer.

The CyberKnife Robotic Radiosurgery System is a robotic radiosurgery system designed to noninvasively treat tumors. Using continual image guidance technology and computer controlled robotic mobility, the CyberKnife System automatically tracks, detects and corrects for tumor and patient movement in real-time throughout the treatment. This enables the CyberKnife System to deliver high-dose radiation with pinpoint precision, which minimizes damage to surrounding healthy tissue and eliminates the need for invasive head or body stabilization frames.

The study, titled "Fractionated Stereotactic Body Radiation Therapy in the Treatment of Primary, Recurrent, and Metastatic Lung Tumors," was conducted at the University of Pittsburgh Medical Center (UPMC) in Pittsburgh, and followed three patient populations over an average 12 month period: 1) patients with primary stage I nonsmall cell lung cancer, 2) patients whose cancer recurred after it was surgically removed, and 3) patients with metastatic tumors in the lung. All patients were treated on an outpatient basis with CyberKnife radiosurgery over a three-day period. These patients had limited treatment options because they were medically inoperable (unable to undergo surgery due to pre-existing medical conditions or prior surgery) or refused surgery.

In the first year following treatment, control of tumor growth was achieved in 85 percent of primary cancer patients, 92 percent of recurrent lung cancer patients, and 62 percent of metastatic cancer patients during the first year of follow-up. The study noted that this is drastically different from response rates for radiation therapy in this patient population, which are typically associated with poor local control and survival rates ranging from 10 to 30 percent at five-year follow-up.

The study also reported few of the complications or side effects that are typical with radiation or other more invasive treatments within the first 12 months of follow-up. In addition, unlike conventional radiation therapy that is typically delivered over four to six weeks, patients completed CyberKnife treatment in three short outpatient visits.

"The CyberKnife System's ability to noninvasively treat lung cancer with favorable local control rates and minimal toxicities make it an important tool in the fight against lung cancer," said Dwight Heron, M.D., chairman of the radiation oncology department at UPMC Shadyside. "As demonstrated by our study, this is particularly important for patients who previously had few or no other options because it gives them a chance for a positive outcome while maintaining their quality of life."

UPMC treated all the study participants using the Synchrony Respiratory Tracking System, which is reportedly the only system in the world that can deliver beams that physically move in real-time with 3D tumor motion. The technology allows patients to breath normally throughout the treatment, while still achieving pinpoint precision and minimizing damage to surrounding healthy tissue. According to the study, Synchrony "can allow for reductions in planning target volume margins because of less movement uncertainty while maintaining the desired level of accuracy."